1. Field of the Invention
The present invention relates to a fiber-reinforced plastic product which is formed from a sheet molding compound, and especially relates to a fiber-reinforced plastic product comprising a bundle of glass fibers which is continuously formed so as to be arranged in the same direction.
2. Description of the Related Art
A conventional fiber-reinforced plastic product related to the present invention is disclosed in Japanese utility model application laid-open publication No. 3(1991)-7027 published without examination on Jan. 23, 1991. In this prior art, a fiber-reinforced plastic product used as a sun-roof housing is formed by pressing from a sheet molding compound (hereinafter referred to as SMC) made of an unsaturated polyester resin including a predetermined additive. Further, a uni directional sheet molding compound (hereinafter referred to as UD-SMC) made of the unsaturated polyester resin is formed by pressing on both surfaces of a portion of the sun-roof housing which should be reinforced. The UD-SMC includes a bundle of glass fibers which is continuously formed so as to be arranged in the same direction. The portion of the sun-roof housing which is located near a window opening formed at a front side of the sun-roof housing is tried to be strengthened by overlaying the UD-SMC on the SMC.
However, in the foregoing sun-roof housing, the UD-SMC is expanded in the lengthwise direction of the sun-roof housing during the press formation thereof, so that the thickness of the UD-SMC is reduced after the press formation. Therefore, it is difficult to assure the strength of the portion of the sun-roof housing which should be reinforced.